A Milwaukee man who turned himself in to police last week for setting his sister on fire has now been charged with her death, according to a criminal complaint.

Nasif Salaam Hibbler, 30, faces one count of first-degree homicide for the June 3 incident, in which authorities found Shakira Hicks, 35, dead in a home in Milwaukee’s north side. If convicted, he could be sentenced to life in prison.

In an interview with Fox 6 earlier this week, two of Hibbler and Hicks’ sisters said Hicks had been diagnosed with cerebral palsy as a baby and was wheelchair-bound for her whole life.

According to the complaint, Hibbler walked into a police station and declared, “I just set my sister on fire,” after which he was taken into custody.

An officer dispatched to the home for a welfare check observed smoke coming out of the lower unit. He discovered Hicks lying on the floor in a fetal position. The officer found that Hicks’ body appeared to be charred. An autopsy later determined her death was a homicide.

Hibbler told police he had been having conversations with other people’s brains, such as those of his family, correctional officers and famous rappers. In an effort to stop “people’s voices,” he said, he eventually sprayed his sister with a bottle of rubbing alcohol before lighting her on fire.

In 2004, Hibbler pleaded guilty to negligent handling of burning material, a misdemeanor. Two years later, he also pleaded guilty to interfering with firefighting equipment.